Refrigerating apparatus



Dec. 22, 1931. m; 1,837,271

REFRIGERATING APPARATUS Filed April 50, 1928 PKG Patented Dec. 22, 1931 UNITED STATES PATENT OFFICE JESSE G. KING, OF DAYTON, OHIO, ASSIGNOR TO FRIGIDAIRE CORPORATION, OF DAYTON,

OHIO, A CORPORATION OF DELAWARE BEJERIGERATING APPARATUS Application filed April 30,

This invention relates to improvements in refrigerating apparatus and more particularly to the compressor-condenser-expander type of apparatus in which a refrigerating met dium is circulated by a compressor drivenby a motor.

It is an object of the invention to provide improved means for preventing overloading of the motive device during starting of the apparatus, particularly after the same has remained idle for a considerable period.

With this object in view the invention contemplates providing means for relieving the load on the compressor by controlling the w pressure'prevailing in the system and particularly the compressor. This is accomplished by providing a thermostatic or temperatureresponsive device'responsive to the temperature within the refrigerating elem ment or cooling unit of the system for shutting ofi the compressor from a portion of the system and for gradually connecting the compressor into the cut-out section.

Further objects and advantages of the pres ent invention will be apparent from the following description, reference bein had to the accompanying drawings, wherein a preferred embodiment of the invention is clearly shown.

9 In the drawings:

Fig. 1 shows a refrigerating system provided with the improved load relief means of the invention;

n Fig. 2 is a cross section through a portion of the refrigerating element of. the system showing the invention applied thereto;

Fig. 3 is a top view of the thermostatic control valve in closed position, and

Fig. 4 is a similar view showing the valve in open position.

Referring in detail to the drawings, the refrigerating system chosen for illustrating the preferred embodiment of the invention comprises an apparatus of the compressorcondenserexpander'type consisting of a compressor 1O driven by a motor 11. This compressor is adapted to force a refrigerating medium such as sulphur dioxide through pipe 12 into a condenser 13 and receiver M. The

refrigerant then passes by way of pipe 15 1928. Serial No. 273,858.

ing ring and closure member 31. This combination is generally referred to as a header and has preferably depending ducts or tubes 17 connected thereto. The liquid refrigerant enters the header through the opening 32 in the lowerportion of the closure plate. The refrigerant, in boiling off in this chamber and the tubes or ducts 17 associated therewith produces its refrigerating effeet in the well known manner. The admission of the refrigerant into the evaporating chamber is controlled by a float operated valve; The preferred form of float valve in the low pressure side as disclosed in the drawings'is composed of the needle valve 33 pivoted on the bracket 34 and controlled by the float ball 18 mounted on the float ball arm 35. By this means a considerable and substantially constant amount of liquid refrigerant is always present in the header. The vaporized refrigerant is drawn ofl' from the chamber 16 by means of pipes 19 and 20 and returned to the compressor. At suitable control switch 21 operated by a flexible expansible body such as a metallic bellows or diaphragm 22 is connected into the suction side of the system and serves to control the operation of the motor and hence of the compressor ill/accordance with the pressure and W therefore temperature conditions prevailing within the evaporating chamber 16.

In the operation of a system of this type, the pressure at the suction end of the line may be quite low, say of the order of a few pounds per square inch, while the pressure at the high side of the line, that is, the condenser and receiver may be very much in excess of this amount. The result is that when the apparatus is allowed to remain idle for any length of time the pressures tend to equalize themselves and upon attempting to start the compressor it will be found that the intake pressure is high and permits more gas to enter which must be compressed and forced into the high pressure side of the line. It is obvious that this pressure imposes a very heavy load on the motor driving the compressor which may be sufficient to stall the motor and either burn out the fuses or else injure the motor.

By means of the present invention, means are provided for preventing the inlet of compressed gas to the com ressor except under desired conditions. This is effected by automatically controlling the high pressure and the means used for accomplishing this result includes a valve which controls the passage of refrigerant from the evaporating chamber 16 to the compressor 10 in accordance with the temperature conditions within the evaporator of the system. .This valve is preferably of the sliding type and as shown in detail in Figs. 3 and a, which show the valve in top view, the valve comprises a disc 23 pivoted as at 24 so as to slidably cover the port 25 which is a passageway providing an opening for the evaporated refrigerant through the opening 36 in the closure plate. A strip of thermostatic metal 26 is rigidly attached to a solid portion such as 27 and is arranged to engage the other extremity of the valve as by two abutments 28. The thermostatic strip is normally curved as disclosed in Fig. a holding the valve 23 to one side of the port 25. When the thermostatic. strip becomes heated and is straightened, it will drag the valve sid'ewise across the port as shown in Fig. 3 where the valve is indicated in a. position directly above said opening. The valve in this position is still slightly spaced from the opening 25 so that a small amount of gas can still enter the port 25. This sliding action does not add any undesirable noise in the operation of the apparatus.

This valve is preferably mounted so as to control the suction line of the refrigerating element as shown in the diagrammatic view of Fig. 1. In the preferredembodiment of the invention the valve 23 is placed so as to control the suction line leading to the evaporating chamber. As shown in Fig. 2 the valve port 25 is the suction valve of the system. The valve 23 is positioned with respect to the seat 25 in which it slides so as to leave a very small clearance which serves as a bleeder passage for the gas so that when the system is started the compressor will withdraw a small quantity of refrigerant in a gaseous condition from the evaporator and gradually reduce the temperature to cause the thermostat 26 to actuate the valve into a position where it is completely open. During the continuous operation of the system the valve is normally maintained in the open eaven position, but if the operation of the system. is interrupted for any length of time sufiicient to permit the evaporating chamber of the refrigerating element to warm up, the

valve will automatically close under the infiuence of the thermostatic strip.

The purpose of the bleeder action or bleeder opening is to throttle'the amount of refrigerant admitted to the'compressor during the starting thereof so that no more refrigerant is admitted than the compressor can take care of. As soon as the operation of the compressor has reduced the pressure of the low side to a point where the temperature of the refrigerating element is reduced, the valve 23 opens and permits normal operation by the compressor.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow What is claimed is as follows:

1. Refrigerating apparatus comprising a system having a low pressure side and a high pressure side, means for circulating refrigerant through said system, said low pressure side including an evaporator of the type having a float actuated valve responsive to the quantity of refrigerant in the low pressure side for controlling the flow of refrigerant from the high pressure side to the evaporator and means providing a passage-- way opening into said evaporator for the return of the evaporated refrigerant and a valve adapted to move from one side of the passageway to the other in a plane slightly spaced from the opening wherebyv the amount of evaporated refrigerant flowing into said passageway may be varied.

2. Refrigerating apparatus comprising a system having a low pressure side and a high pressure -side, means for circulating refrigerant through said system, said low pressure side including an evaporator of the type having a float actuated valve responsive to the quantity of refrigerant in the low pressure side for controlling the flow of refrigerant from the high pressure side to the evaporator and means providin a passageway opening into said evaporator for the return of the evaporated refrigerant and a valve adapted to move fromone side of the passageway to the other in a plane slightly are spaced from the opening whereby the amount i of evaporated refrigerant flowing into said passageway may be varied and a therm'ostatic strip adapted to move said valve according to the temperature in said evaporator. Y

3. A cooling unit comprising a tank, a closure member for said tank, said closure member having an inlet for liquid refrigerant, a float valve in said tank adapted to maintain a predetermined quantity of liquid refrigerant therein, said.closure member also having a passageway for evaporated refrigerant, and a valve adapted to slide over the entrance to said passageway in a plane from one side of the entrance to another.

4. A .cooling unitcomprising a tank, a closure member for said tank, said closure member having an inlet for li uid refrigerant, a float valve in said tan .adapted to maintain a predetermined quantity of liquid refrigerant therein. said closure member having a passageway for evaporated refrigerant, and a valve adapted to slide in a plane from one side to the other over the en-. trance to said passageway and a thermostatic strip adapted to actuate thesliding motion of said valve.

5. Refrigerating apparatus including an evaporator, means for supplying refrigerant to the evaporator. and means providing a passageway opening into said evaporator for the return of the evaporated refrigerant and a valve adapted to move from one side of the passageway to the other in a plane slightly spaced from the opening whereby the amount of evaporated refrigerant flowing into said passageway may be varied.

6. Refrigerating apparatus including an evaporator, means for supplying refrigerant to the evaporator. and means providing a passageway opening into said evaporator for the return of the evaporated refrigerant vand a valve adapted to move from one side of the passageway to the other in a plane slightly spaced from the opening whereby the amount of evaporated refrigerant flowing into said passageway may be variedand a thermostatic strip adapted to move said valve according to the temperature within the evaporator.

7. A cooling unit comprising a tank, a closure member for said tank. said closure member having an inlet for said closure member also having a passageway for evaporated refrigerant. and a valve adapted to slide over the entrance to said passageway in a plane from one side of the entrance to another.

8' A cooling unit comprising a tank. a closure member for said tank, said closure member having an inlet for liquid refrigerant, said closure member also having a passageway for evaporated refrigerant, and a valve adapted to slide over the entrance to said passageway in a plane from one side of the entrance to another and a thermostatic strip adapted to actuate said valve.

In testimony whereof I hereto afiix my signature.

JESSE G. KING. I

liquid refrigerant, 

